NEWS

Seismic survey of Kaštela Bay and Split Channel within the scope of the Internal research project “Rivers Into MAD” (RIM)

June 2025 marks the first geophysical survey this year, for the Internal research project Rivers Into MAD. The survey was deployed over the area of the Brač Channel and the Gulf of Kaštela. The Project aims to define submerged paleolandscapes surrounding two karst rivers in central Dalmatia – Jadro and Cetina, that formed during the Quaternary, and answer whether those rivers flowed into the Mid-Adriatic Deep (MAD) during the Last Glacial Maximum.

This year’s survey was focused on areas not covered or not sufficiently covered during the previous fieldtrips.

The focus in the Gulf of Kaštela was on submerged springs (vruljas) Arbanija and Slatina and detailed mapping of the NW part of the Gulf. The survey in the Brač Channel was the continuation of last season’s surveys that included the submerged region of the river Žrnovnica, the area that was missing in the previous surveys. We used a sub-bottom profiler (INNOMAR SES 2000) and multi-beam echosounder (WASSP S3) to collect 137.5 km of geophysical data, which completely fulfilled the planned objectives. The project continues with data processing and interpretation, as well as with an initial paleoenvironmental reconstruction based on seismic data. Future coring surveys are planned in the autumn season, which will include piston coring using our platform Q2.

On the last day of the survey, we welcomed professors and students from the Oklahoma State University (USA) who attended an excursion organized and led by academian Goran Durn and Dr. sc. Ivor Perković from the Faculty of Mining, Geology and Petroleum Engineering. Seven students, a PhD student, two professors, and organizers were introduced to the aims of the project Rivers into Mad, as well as to the methods and basic use of the instruments onboard the vessel.

The crew onboard the vessel “Dide Rak” comprised Dr. sc. Slobodan Miko, Dr. sc. Natalia Smrkulj, Dr. sc. Ozren Hasan and Captain Mile Jerat. This research was conducted in the scope of the internal research project „Rivers Into MAD - Resolving the Jadro and Cetina palaeoriver landscapes during the Last Glacial Maximum (RIM)“ at the Croatian Geological Survey, funded by the National Recovery and Resilience Plan 2021–2026 of the European Union – NextGenerationEU, and monitored by the Ministry of Science and Education of the Republic of Croatia.

Introduction of the Project for the students of the Oklahoma State University (USA).

Partially processed sub-bottom profile collected at the location of the vrulja Slatina in the Gulf of Kaštela.